1. Technical Field
The present disclosure relates generally to a method and a system related to performing optical vector analysis. In particular, the present disclosure relates to a method and a system suitable for determining a transfer function of an optical device at various operating frequencies.
2. Discussion of Technical Background
Optical vector analysis may be performed to determine a transfer function of an optical device at various operating frequencies of the optical device. The transfer function of the optical device may also be referred to as a transmission response of the optical device, indicating a relationship, caused by the optical device, between an input signal received by the optical device and an output signal outputted by the optical device. The transfer function of the optical device may be further used to determine a plurality of characteristics of the optical device at the various operating frequencies. Examples of the characteristics may include, but not limited to, insertion loss, dispersion, group delay, polarization dependent loss, and polarization mode dispersion.
A traditional method for performing the optical vector analysis on the optical device may be based on a single sideband modulation of an optical signal passing through the optical device. The single sideband modulation may be implemented by performing double sideband modulation on the optical signal, followed by a suitable process for keeping one sideband on one side of each carrier frequency of the optical signal while suppressing the sideband on the other side of the carrier frequency. However, it is extremely difficult to eliminate one of the two sidebands associated with each carrier frequency completely for achieving an ideal single sideband modulation, which results in a limited dynamic range and accuracy for the optical vector analysis. Therefore, there is a need for an improved method and apparatus for performing the optical vector analysis.